It is desired to rapidly determine the velocity of high speed reentry vehicles (RV's). The current systems require a tracking of the RV to compute the speed or lapsed time measurement from a pulsed LASER system. Both these systems must have uninterrupted line of site contact with the RV during the measurement sequence. An obscured pulse in the time measurement system would result in the considerable error in the computed velocity or no reading at all. For the system presented in this disclosure, accuracy is not affected by momentary drop out in the signal being processed. This system can measure very high velocities with a minimum of time on the target vehicle. It will quickly give the velocity of either an incoming or outgoing target (with respect to the observation platform).